I just came across a old tube amp and I got it working but after it warms up good it starts this real high pitched squell.Any thoughts on what might be causing this ?
I movedd your first thread on this subject – you’re not reading the forum listings to see where you should be appropriately placing your threads.
I’ll move this one but take a look at the forum page and get a better idea of where things are supposed to go, please.
a bad tube can do that.
capacitors, resistors and connections can also be bad and do that.
Look at the tubes when it’s powered up. Sometimes a bad tube will glow more or less than the others and that can be a good indication of a likely culprit. Then try lightly tapping each tube with a pencil and see if one makes a racket when tapped. Gently. If you find one that’s suspicious try replacing it with a new one of the same type.
If no luck there, take it to a pro.
Quite possibly the OP misread the local moderator as TubeDiva and thought that it was the best way to reach you.
Sounds like you have a microphonic tube, dude.
Good link E-Sabbath. That’s most likely the issue.